> On Nov 8, 2022, at 2:18 AM, Mattias Engdegård <mattiase@acm.org> wrote:
>
> 7 nov. 2022 kl. 21.35 skrev Yuan Fu <casouri@gmail.com>:
>
>> fast_c_string_match_ignore_case (Lisp_Object regexp,
>> const char *string, ptrdiff_t len)
>> {
>> regexp = string_make_unibyte (regexp);
>
> This is expensive and not obviously correct when it makes a difference. Ie,
> no longer "fast", and may hide bugs.
> Something should be done about that.
>
>> // Why do we need to unwind stack?
>> specpdl_ref count = SPECPDL_INDEX ();
>
> Because freeze_pattern pushes an unwind-protect on the specpdl.
>
>> struct regexp_cache *cache_entry
>> = compile_pattern (regexp, 0, Vascii_canon_table, 0, 0);
>
> `Vascii_canon_table` is what makes it case-insensitive; you want to use Qnil
> (but you probably already know that now).
> Since this is the only thing that differs from your intended use, I suggest
> you generalise this subroutine with a boolean parameter.
>
>> // What does freezing a pattern do?
>> freeze_pattern (cache_entry);
>
> It locks the compiled pattern record to make the regexp engine reentrant (but
> here it also seems to be used for GC purposes; not sure about that).
>
>> // What is re_match_object for? I see that it can be t, nil or a string.
>> re_match_object = Qt;
>
> Described in regex-emacs.h:
>
>> /* The string or buffer being matched.
>> It is used for looking up syntax properties.
>>
>> If the value is a Lisp string object, match text in that string; if
>> it's nil, match text in the current buffer; if it's t, match text
>> in a C string.
>>
>> This value is effectively another parameter to re_search_2 and
>> re_match_2. No calls into Lisp or thread switches are allowed
>> before setting re_match_object and calling into the regex search
>> and match functions. These functions capture the current value of
>> re_match_object into gl_state on entry.
>>
Thanks! How about:
Yuan
c_string_match.diff
Description: Binary data
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4